Linux disk management
Linux disk management directly related to the quality of management performance of the whole system.
Linux disk management commands of three commonly used df, du, and fdisk.
- df: Lists overall disk usage of the file system
- du: Check the amount of disk space usage
- fdisk: for partition
df
df command parameters Function: Check the file system disk space occupancy. You can use this command to obtain the hard drive is taking up much space, how much space is still remaining and other information.
grammar:
df [-ahikHTm] [目录或文件名]
Options and parameters:
- -a: List all file systems, including the system-specific / proc file system, etc;
- -k: KBytes capacity to display all file system;
- -m: MBytes capacity to display all file system;
- -h: It is easier to read GBytes, MBytes, KBytes own display formats;
- -H: M = 1000K to replace M = 1024K carry manner;
- -T: Displays the file system type, together with the name of the partition of the filesystem (such as ext3) are also listed;
- -i: without hard drive capacity, and to the inode number to display
Example 1
The system will all the file systems listed!
[root@www ~]# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/hdc2 9920624 3823112 5585444 41% / /dev/hdc3 4956316 141376 4559108 4% /home /dev/hdc1 101086 11126 84741 12% /boot tmpfs 371332 0 371332 0% /dev/shm
Linux df underneath if not add any options, then the system will default within all (excluding special file systems and swap memory inside) are in 1 Kbytes capacity to be listed!
Example 2
The capacity results are displayed in an easy-capacity format
[root@www ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/hdc2 9.5G 3.7G 5.4G 41% / /dev/hdc3 4.8G 139M 4.4G 4% /home /dev/hdc1 99M 11M 83M 12% /boot tmpfs 363M 0 363M 0% /dev/shm
Example 3
All special file formats and names are listed in the system
[root@www ~]# df -aT Filesystem Type 1K-blocks Used Available Use% Mounted on /dev/hdc2 ext3 9920624 3823112 5585444 41% / proc proc 0 0 0 - /proc sysfs sysfs 0 0 0 - /sys devpts devpts 0 0 0 - /dev/pts /dev/hdc3 ext3 4956316 141376 4559108 4% /home /dev/hdc1 ext3 101086 11126 84741 12% /boot tmpfs tmpfs 371332 0 371332 0% /dev/shm none binfmt_misc 0 0 0 - /proc/sys/fs/binfmt_misc sunrpc rpc_pipefs 0 0 0 - /var/lib/nfs/rpc_pipefs
Example 4
The available disk capacity / etc under the display to readable volume format
[root@www ~]# df -h /etc Filesystem Size Used Avail Use% Mounted on /dev/hdc2 9.5G 3.7G 5.4G 41% /
du
inux du command also view the use of space, but with the df command is different Linux du command files and directories using disk space to view, or df command and there are some differences, here Linux du command.
grammar:
du [-ahskm] 文件或目录名称
Options and parameters:
- -a: lists all files and directories capacity because only the amount of the default file directory under the statistics only.
- -h: It is easier to read the volume format (G / M) display;
- -s: Lists the total amount of it, rather than listing each respective directory occupancy capacity;
- -S: Total does not include subdirectories, and -s bit different.
- -k: listed in KBytes capacity display;
- -m: In MBytes listed capacity display;
Example 1
List all the file size of the current directory
[root@www ~]# du 8 ./test4 <==每个目录都会列出来 8 ./test2 ....中间省略.... 12 ./.gconfd <==包括隐藏文件的目录 220 . <==这个目录(.)所占用的总量
No direct input du plus any options, then du analyzes the current directory of files and directories occupied hard disk space.
Example 2
The document also listed capacity
[root@www ~]# du -a 12 ./install.log.syslog <==有文件的列表了 8 ./.bash_logout 8 ./test4 8 ./test2 ....中间省略.... 12 ./.gconfd 220 .
Example 3
Check under the root directory of each occupied capacity
[root@www ~]# du -sm /* 7 /bin 6 /boot .....中间省略.... 0 /proc .....中间省略.... 1 /tmp 3859 /usr <==系统初期最大就是他了啦！ 77 /var
The wildcard * to represent each directory.
And df is not the same, du fact, this command directly into the file system to search for all of the file data.
fdisk
fdisk is a Linux disk partition table manipulation tools.
grammar:
fdisk [-l] 装置名称
Options and parameters:
- -l: All contents of the partition behind the output connected devices. If only fdisk -l, then the system will be able to search the entire system partition to the device are listed.
Example 1
List all partition information
[root@AY120919111755c246621 tmp]# fdisk -l
Disk /dev/xvda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/xvda1 * 1 2550 20480000 83 Linux
/dev/xvda2 2550 2611 490496 82 Linux swap / Solaris
Disk /dev/xvdb: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x56f40944
Device Boot Start End Blocks Id System
/dev/xvdb2 1 2610 20964793+ 83 Linux
Example 2
Find out what your system disk root directory resides, and access to relevant information about the hard disk inside
[root@www ~]# df / <==注意：重点在找出磁盘文件名而已 Filesystem 1K-blocks Used Available Use% Mounted on /dev/hdc2 9920624 3823168 5585388 41% / [root@www ~]# fdisk /dev/hdc <==仔细看，不要加上数字喔！ The number of cylinders for this disk is set to 5005. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Command (m for help): <==等待你的输入！
After entering m, you will see the introduction of these commands under
Command (m for help): m <== 输入 m 后，就会看到底下这些命令介绍 Command action a toggle a bootable flag b edit bsd disklabel c toggle the dos compatibility flag d delete a partition <==删除一个partition l list known partition types m print this menu n add a new partition <==新增一个partition o create a new empty DOS partition table p print the partition table <==在屏幕上显示分割表 q quit without saving changes <==不储存离开fdisk程序 s create a new empty Sun disklabel t change a partition's system id u change display/entry units v verify the partition table w write table to disk and exit <==将刚刚的动作写入分割表 x extra functionality (experts only)
Press to leave the fdisk q , then all the action will not take effect! Instead, press the w is the meaning of the action to take effect.
Command (m for help): p <== 这里可以输出目前磁盘的状态 Disk /dev/hdc: 41.1 GB, 41174138880 bytes <==这个磁盘的文件名与容量 255 heads, 63 sectors/track, 5005 cylinders <==磁头、扇区与磁柱大小 Units = cylinders of 16065 * 512 = 8225280 bytes <==每个磁柱的大小 Device Boot Start End Blocks Id System /dev/hdc1 * 1 13 104391 83 Linux /dev/hdc2 14 1288 10241437+ 83 Linux /dev/hdc3 1289 1925 5116702+ 83 Linux /dev/hdc4 1926 5005 24740100 5 Extended /dev/hdc5 1926 2052 1020096 82 Linux swap / Solaris # 装置文件名 启动区否 开始磁柱 结束磁柱 1K大小容量 磁盘分区槽内的系统 Command (m for help): q
Want to leave without saving it? Press q on the right! Do not press w ah!
Use p to list the current partition table information Fengyun disk, the information in the upper half shows the overall status of the disks.
Disk Format
After the completion of the natural disk partition is formatted to the file system, formatted command is very simple to use mkfs (the make filesystem) command.
grammar:
mkfs [-t 文件系统格式] 装置文件名
Options and parameters:
- -t: You can access the file system format, such as ext3, ext2, vfat, etc. (support system to take effect)
Example 1
See mkfs supported file formats
[root@www ~]# mkfs[tab][tab] mkfs mkfs.cramfs mkfs.ext2 mkfs.ext3 mkfs.msdos mkfs.vfat
Press the two [tab], as shown above mkfs will find supported file formats.
Example 2
Partition / dev / hdc6 (you can specify your own partition) formatted as ext3 file system:
[root@www ~]# mkfs -t ext3 /dev/hdc6
mke2fs 1.39 (29-May-2006)
Filesystem label= <==这里指的是分割槽的名称(label)
OS type: Linux
Block size=4096 (log=2) <==block 的大小配置为 4K
Fragment size=4096 (log=2)
251392 inodes, 502023 blocks <==由此配置决定的inode/block数量
25101 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=515899392
16 block groups
32768 blocks per group, 32768 fragments per group
15712 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Creating journal (8192 blocks): done <==有日志记录
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 34 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
# 这样就创建起来我们所需要的 Ext3 文件系统了！简单明了！
Disk Test
fsck (file system check) to check and maintain inconsistent file system.
If the system power failure or disk problems occur, you can use the fsck command to check the file system.
grammar:
fsck [-t 文件系统] [-ACay] 装置名称
Options and parameters:
- -t: given type of file system, or kernel itself has been defined to support if the / etc / fstab is not required in this parameter plus
- -s: sequentially one by one to check the fsck command execution
- -A: To / etc / fstab partitions (partition) to do all the listed checks
- -C: Display a complete check progress
- -d: debug print out the results of e2fsck
- -p: -A condition at the same time there is, there are multiple fsck checks performed together
- -R: -A Condition when both have omitted / not checked
- -V: Detailed display mode
- -a: If the check is wrong automatically repair
- -r: Check if the answer is wrong by the user repair
- -y: option specifies the detection of each file is automatically entered yes, the uncertainty that is not normal, they can perform all the checks # fsck -y repair.
Example 1
See how many file system supported by the system fsck command:
[root@www ~]# fsck[tab][tab] fsck fsck.cramfs fsck.ext2 fsck.ext3 fsck.msdos fsck.vfat
Example 2
Mandatory testing / dev / hdc6 Subdivision:
[root@www ~]# fsck -C -f -t ext3 /dev/hdc6 fsck 1.39 (29-May-2006) e2fsck 1.39 (29-May-2006) Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information vbird_logical: 11/251968 files (9.1% non-contiguous), 36926/1004046 blocks
If you do not add the -f option, since the file system did not have problems, check through a very fast! -f If coupled with mandatory testing process will display one by one.
Disk mount and dismount
Linux disk mounted using the mount command, uninstall using the umount command.
Disk mount syntax:
mount [-t 文件系统] [-L Label名] [-o 额外选项] [-n] 装置文件名 挂载点
Example 1
The default way that will just create / dev / hdc6 mount / mnt / hdc6 above!
[root@www ~]# mkdir /mnt/hdc6 [root@www ~]# mount /dev/hdc6 /mnt/hdc6 [root@www ~]# df Filesystem 1K-blocks Used Available Use% Mounted on .....中间省略..... /dev/hdc6 1976312 42072 1833836 3% /mnt/hdc6
Disk uninstall command umount syntax:
umount [-fn] 装置文件名或挂载点
Options and parameters:
- -f: Force dismount! Available in the case of a similar network file system (NFS) can not be read to;
- -n: do not upgrade at / etc / mtab situation dismounted.
Uninstall / dev / hdc6
[root@www ~]# umount /dev/hdc6